#include<bits/stdc++.h>
using namespace std;
int n, dp[200005];
pair<int, int> a[200005];
int main() {
cin >> n;
for (int i = 1; i <= n; i++) {
cin >> a[i].first;
a[i].second = 0;
}
for (int i = n + 1; i <= n * 2; i++) {
cin >> a[i].first;
a[i].second = 1;
}
sort(a + 1, a + 2 * n + 1);
/// 0 : mau den
/// 1 : mau trang
for (int i = 2; i <= 2 * n; i++) {
/// TH1 : ko noi duoc
dp[i] = dp[i - 1];
/// TH2 : noi duoc
if (a[i].second != a[i - 1].second)
dp[i] = max(dp[i], dp[i - 2] + 1);
}
cout << dp[2 * n];
}
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